Oh, while you're at it... leave a gift of an Amazon.com review (or your other favorite online sites) of your favorite authors' books.
Of course 5's and aboves are extremely nice. But any kind or constructive reviews (how it resonated with you, your favorite parts, what it made you think about, how it's different or similar to the authors other works) will help other readers...
And the authors appreciate it too! I just did some for Eric Jerome Dickey, Johnny Diaz, and a few other new favorites.